febootstrap-to-initramfs: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/febootstrap-to-initramfs - from package: febootstrap

You may install the required package with command yum install {package}

Error in other languages:
febootstrap-to-initramfs: bevel nie gevind nie
febootstrap-to-initramfs: comandă negăsită
febootstrap-to-initramfs: comando não encontrado
febootstrap-to-initramfs: commande introuvable
febootstrap-to-initramfs: command not found
febootstrap-to-initramfs: käsku ei ole
febootstrap-to-initramfs: không tìm thấy lệnh
febootstrap-to-initramfs: komanda nerasta
febootstrap-to-initramfs: Kommando nicht gefunden.
febootstrap-to-initramfs: kommandot finns inte
febootstrap-to-initramfs: komut yok
febootstrap-to-initramfs: nie znaleziono polecenia
febootstrap-to-initramfs: níor aimsíodh an t-ordú
febootstrap-to-initramfs: no se encontró la orden
febootstrap-to-initramfs: no s'ha trobat l'ordre
febootstrap-to-initramfs: opdracht niet gevonden
febootstrap-to-initramfs: parancs nem található
febootstrap-to-initramfs: perintah tidak ditemukan
febootstrap-to-initramfs: príkaz nenájdený
febootstrap-to-initramfs: příkaz nenalezen
febootstrap-to-initramfs: команда не найдена
febootstrap-to-initramfs: командата не е открита
febootstrap-to-initramfs: 命令找不到
febootstrap-to-initramfs: コマンドが見つかりません